Coal to Ash Calculation (Volume)

If you have a piece of the coal in question you should be able to burn it and determine the value for yourself (are you sure you need the volumetric value?)

Other than that we would at least have to know what coal it is as there will be huge differences for the different kinds.

After a quick Google search, it appears that both fly ash and bottom ash both have a bulk density of about 1 ton per cubic meter.

So, using your figure of 20% ash, if five tons of coal were burnt roughly 1 cubic meter of ash would remain.

Burning coal produces a lot of problematic emissions. I am very vocal in my opposition to the use of coal for power.

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The reason I told you that is to let you know you can trust me when I tell you your estimate of 20% of the weight of burned coal ending up as ash. It is probably much closer to 10% in most situations.

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Just so we are clear, coal can definitely be burned incompletely resulting in 20% weight ash, but any modern well run plant won't be wasting 10% of their fuel.

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EDIT: Here is one reasonable source that supports/confirms ash being closer 10% weight.

I'm having regrets about calling that reference 'reasonable', though on the 10% ash by weight, the information seems reliable.

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The US burns around a billion tons of coal annually which produces around 100 million tons of solid combustion by products, little over half of which is fly ash, most of the rest being bottom ash.

I am sure that the amount of ash depends also upon coal quality, how much stone or other un-burnable products are part and parcel of the coal?

Hilt's law

It is said "the deeper the coal, the better the quality!" So it also depends upon how deep it is taken from to a degree.....

The lesser the quality in that regard = more left over as ash.....but probably also as big lumps of melted stone that were used in buildings and roads and in my youth at least. We called it "Clinker".

(Clinker is defined as:- "Clinkers have been a recurring problem in all coal-fired boilers for as long as humans have operated coal boilers. Clinkers occur in small stoves used for heating a home and in giant commercial/industrial boilers. Clinkers, also known as slag, consist of the noncombustible elements and minerals found in coal that melt and fuse together as lumpy ashes from coal combustion. Boiler operators consider clinkers to be miserable stuff." Read more: http://www.ehow.com/info_12152358_causes-clinkers-coal-fired-boilers.html#ixzz2sT65EUVg)

I know that price and quality go hand in hand in any industry and I would suspect that some companies are going to try and save money by buying cheaper low quality coal and expect to have to get rid of larger quantities of ash and clinker.....

As a start, see here:-

http://en.wikipedia.org/wiki/Coal

and here:-

http://en.wikipedia.org/wiki/Coal_assay

I would guess that a full test needs to be made to assess the amount of ash that is ACTUALLY produced from a specific coal type.....nothing else will be accurate.

I would imagine that it will vary greatly on two factors. What grade of coal [lignite, bituminous, anthracite, or refined coal] is being burned and the burning process [how hot] used to burn the coal. I would be very surprised if bottom ash of any coal and burning process would be 1/5 of the original volume or weight of coal. The resulting final density (mass divided by volume) of bottom ash maybe nominally 1/5 of the density of coal. I would expect many numbers of metric tons of coal would have to be burned to produce one kilogram of bottom ash.

"...I would expect many numbers of metric tons of coal would have to be burned to produce one kilogram of bottom ash...."

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That expectation would result in significant surprise.

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One kilogram of the cleanest typical natural coal coal burnt completely would create around 50 grams of ash at a minimum, at least 5 grams of which would be bottom ash.

Viking, Engineering college teaches basics, it is experience which counts more. Machinist with long experience is more knowledgeable than fresh engineer. I hope all will agree with me. So do not get demoralised if you are not engineer.

"Objection!

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Your Honorableness, it is clear that Barrister Lyn is trying to mislead this perfectly professional witness in an attempt to unduly influence the ladies and gentlemen of the supposed jury! He claims erroneously that nothing produced here in CR4 would have any legal standing. Lyn knows full well the comments here at a minimum have legal standing as hearsay and inadmissible. I urge you to set an example showing everyone that tactics like logic and sound advice will not be tolerated in the court of aggravated ignorance."

Contempt of Court!

You are sentenced to 2 minutes on the naughty step, second level!!

Your Honor, as pro-facto representative of the accused, I throw him prostate on the mercy of the court.....and plead insanity!

Conversion tables are well known and easily found if one knows:

How to Search the Internet - Hannon Library

Units Converter for Specific Gravity - Calculator.org

How to Find Volume when Given Mass and Specific Gravity

By using these calculators, and showing your work, you have something that will stand up in court.

The only thing left is to determine the SG of the coal.

There is a whole raft of information on coals in Kempe's Engineer's Yearbook, any edition.

The last sample I had an analysis performed on was 4.52% ash by weight.

The plant burning the coal in question should have an average % ash content. The maximum ash content is usually a contractual obligation of the coal supplier.

It also depends on the quality of the coal you are using. There are coals which have less ash content but are expensive.

The answer you seek is very simple to obtain. I presume that this relates to a specific case/plant; consequently, it will relate to a specific range of fuels as coal fired power plants are designed to burn a specific range of fuels. So your investigating steps are as follows:

1. determine the specific fuel used at the plant your are investigating.

2. obtain a proximate analysis (this will show the percent of ash in fuel). Fuels can range from less than 10% to over 50% by volume so this is important.

3. determine the average tons per day of fuel fired.

4. find the "capacity factor" (how many days/year the plant runs at full load)

5. calculate the total ash generated and extrapolate for an annual total.

Forgot to get you to cubic meters ... multiply tons by ~0.64 to convert to volume in cubic meters.

"....multiply tons by ~0.64 to convert to volume in cubic meters....."

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Wow! That is handy. Very useful indeed. For example, merely reading was very useful in providing the opportunity to enjoy a good chuckle.

That is clever.

A universal weight to volume conversion factor.

The astronauts on the ISS must be incredibly tiny in the microgravity environment! I bet that helps to reduce the risk of being hit by space debris...but I'm surprised they don't lose track of more of them.

Does this mean that the lunar modules and the Mars rovers occupy at least three different volumes.

no, not a "universal weight to volume conversion factor" I just looked up the average density for coal ash.